Whatever the code was--whether it was someone's bank code, or a password to an account--whatever it was, Fontaine was willing to pay for each one--if they cost less than $1000. Chad chuckled, or laughed. We don't know why Chad laughed--maybe it was because Fontaine was so rich that he could pay up to $1000 for each code that he bought. Maybe he chuckled because Fontaine was a fool for paying so much for codes that would not render that much money in return. Maybe he chuckled or laughed because it was like "fishing in a barrel," $1000 was cheap for what Fontaine was getting in return.